Kamis, 06 Oktober 2011

Take Assessment - ENetwork Chapter 9 - CCNA Exploration 1: Network Fundamentals (Version 4.0) [Oktober 2011]

1. Host A has an IP address of 172.16.225.93, a mask of 255.255.248.0, and a default gateway of 172.16.224.1. Host A needs to send a packet to a new host whose IP is 172.16.231.78. Host A performs the ANDing operation on its address and subnet mask. What two things will occur? (Choose two.) 
  • Host A will get a result of 172.16.224.0 from the AND process. 
  • Host A will send on to the media a broadcast frame that contains the packet. 
  • Host A will broadcast an ARP request for the MAC of the host 172.16.231.78. 
  • Host A will change the destination IP of the packet to 172.16.224.1 and forward the packet. 
  • Host A will encapsulate the packet in a frame with a destination MAC that is the MAC address associated with 172.16.224.1.
2. What does the IEEE 802.2 standard represent in Ethernet technologies?
  • MAC sublayer
  • Physical layer
  • Logical Link Control sublayer
  • Network layer
3.
In the graphic, Host A has reached 50% completion in sending a 1 KB Ethernet frame to Host D when Host B wishes to transmit its own frame to Host C. What must Host B do?
  • Host B can transmit immediately since it is connected on its own cable segment.
  • Host B must wait to receive a CSMA transmission from the hub, to signal its turn.
  • Host B must send a request signal to Host A by transmitting an interframe gap.
  • Host B must wait until it is certain that Host A has completed sending its frame.
4. Which statements correctly describe MAC addresses? (Choose three.)
  • dynamically assigned 
  • copied into RAM during system startup 
  • layer 3 address 
  • contains a 3 byte OUI 
  • 6 bytes long 
  • 32 bits long
5. Ethernet operates at which layers of the OSI model? (Choose two.)
  • Network layer
  • Transport layer
  • Physical layer
  • Application layer
  • Session layer
  • Data-link layer
6. Which of the following is a drawback of the CSMA/CD access method?
  • Collisions can decrease network performance.
  • It is more complex than non-deterministic protocols.
  • Deterministic media access protocols slow network performance.
  • CSMA/CD LAN technologies are only available at slower speeds than other LAN technologies.
7.
Refer to the exhibit. The switch and workstation are administratively configured for full-duplex operation. Which statement accurately reflects the operation of this link?
  • No collisions will occur on this link.
  • Only one of the devices can transmit at a time.
  • The switch will have priority for transmitting data.
  • The devices will default back to half duplex if excessive collisions occur.
8. After an Ethernet collision, when the backoff algorithm is invoked, which device has priority to transmit data?
  • the device involved in the collision with the lowest MAC address
  • the device involved in the collision with the lowest IP address
  • any device in the collision domain whose backoff timer expires first
  • those that began transmitting at the same time
9. Convert the binary number 10111010 into its hexadecimal equivalent. Select the correct answer from the list below. 
  • 85 
  • 90 
  • BA 
  • A1 
  • B3 
  • 1C
10. What are the two most commonly used media types in Ethernet networks today? (Choose two.)
  • coaxial thicknet
  • copper UTP
  • coaxial thinnet
  • optical fiber
  • shielded twisted pair
11. Which of the following describe interframe spacing? (Choose two.)
  • the minimum interval, measured in bit-times, that any station must wait before sending another frame
  • the maximum interval, measured in bit-times, that any station must wait before sending another frame
  • the 96-bit payload padding inserted into a frame to achieve a legal frame size
  • the 96-bit frame padding transmitted between frames to achieve proper synchronization
  • the time allowed for slow stations to process a frame and prepare for the next frame
  • the maximum interval within which a station must send another frame to avoid being considered unreachable
12.
Refer to the exhibit. Host_A is attempting to contact Server_B. Which statements correctly describe the addressing Host_A will generate in the process? (Choose two.)
  • A packet with the destination IP of Router_B. 
  • A frame with the destination MAC address of Switch_A. 
  • A packet with the destination IP of Router_A. 
  • A frame with the destination MAC address of Router_A. 
  • A packet with the destination IP of Server_B. 
  • A frame with the destination MAC address of Server_B.
13.
Refer to the exhibit. Which option correctly identifies content that the frame data field may contain?
  • preamble and stop frame
  • network layer packet
  • physical addressing
  • FCS and SoF
14. When a collision occurs in a network using CSMA/CD, how do hosts with data to transmit respond after the backoff period has expired?
  • The hosts return to a listen-before-transmit mode.
  • The hosts creating the collision have priority to send data.
  • The hosts creating the collision retransmit the last 16 frames.
  • The hosts extend their delay period to allow for rapid transmission.
15. What three primary functions does data link layer encapsulation provide? (Choose three.)
  • addressing
  • error detection
  • frame delimiting
  • port identification
  • path determination
  • IP address resolution
16. What is the primary purpose of ARP?
  • translate URLs to IP addresses
  • resolve IPv4 addresses to MAC addresses
  • provide dynamic IP configuration to network devices
  • convert internal private addresses to external public addresses
17. Which two features make switches preferable to hubs in Ethernet-based networks? (Choose two.)
  • reduction in cross-talk
  • minimizing of collisions
  • support for UTP cabling
  • division into broadcast domains
  • increase in the throughput of communications
18. Why do hosts on an Ethernet segment that experience a collision use a random delay before attempting to transmit a frame?
  • A random delay is used to ensure a collision-free link.
  • A random delay value for each device is assigned by the manufacturer.
  • A standard delay value could not be agreed upon among networking device vendors.
  • A random delay helps prevent the stations from experiencing another collision during the transmission.
19. Ethernet operates at which layer of the TCP/IP network model?
  • application
  • physical
  • transport
  • internet
  • data link
  • network access
20. What are three functions of the upper data link sublayer in the OSI model? (Choose three.)
  • recognizes streams of bits
  • identifies the network layer protocol
  • makes the connection with the upper layers
  • identifies the source and destination applications
  • insulates network layer protocols from changes in physical equipment
  • determines the source of a transmission when multiple devices are transmitting

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